Upon arrival, the participant completed a questionnaire to confirm compliance with 48-hour drug and alcohol abstinence instructions and 3-hour abstinence from food, caffeine, and smoking. Participants underwent several objective tests to verify compliance with pretesting instructions; these tests included carbon monoxide (<10 ppm) and alcohol breathalyzer tests and, before at least 1 session, a urine toxicology screen. Women also undertook a urinary human chorionic gonadotropin test to verify nonpregnancy before each session. After these tests, the participant consumed a low-fat snack at 20% of daily kilocalorie needs, based on a macronutrient distribution of 55% of kilocalories from carbohydrates, 10% from protein, and 35% from fat.66
